The present invention relates in general to photography equipment and in particular to a film holder apparatus for the facilitated introduction and positive maintenance of one or more sheets of photographic film within field and studio photography cameras.
Ever since the end of the late 19th Century, photographers have relied upon the large format field or studio camera for purposes of photographing subjects onto substantially large negatives, which are in turn developed into photographs of equivalent size. Utilization of such large format photography techniques offers substantial photographic detail, depth and other known and desired benefits to such photographs.
In association with such photography techniques, and particularly in association with such large format photography devices, film holders have been utilized at the backs of such cameras to removably maintain sheets of film in place for manual loading, photographing, and manual removal therefrom. For many years, such conventional large format film holding devices have invariably maintained two sheets of film in position within a film holder "cartridge", permitting the photographer to expose one sheet of film, to cover it from the dark for removing and reversing the position of the holder. At this point, the second film sheet is positioned, upon removal of a dark slide protective screen, for operation of the camera lens aperture and subsequent exposure of that second sheet of film. Such a film holder apparatus "cartridge" has typically been positionable at the rear of the camera so as to place the sheets of film on a substantially firm planar support at a position equivalent to the location of the ground glass plate, on which an image is preliminarily focused. With such large format photographic camera devices, the photographer will focus on its subject until the image is appropriately displayed on the ground glass focusing element within the camera. At the time of proper focus, the film holder apparatus is inserted into the back of the camera after movement of the spring biased focusing surface, in which a planar supporting surface within the film holder is capable of maintaining the film at a position closely proximate to the previous "focused" position upon the ground glass.
In the majority of prior art film holder apparata, the one or two film sheets maintained within the cartridge were maintained relatively "freely" in a substantially narrow groove without positive locked maintenance to prevent against shifting or "migration" of the film within the holder. This construction would often result in movement, sliding or "bowing" of the film about its longitudinal axis. Such potential movement, sliding and bowing would often result in potential distortions in the photograph to frustrate focusing accuracy as originally attempted when focusing the camera.
Yet additional problems have been experienced with conventional and prior art film holder apparata for such large format cameras by way of deterioration often experienced with fabric-hinged film access gates. Undesirable leakage of light into various abutting edge locations on such devices would often adversely affect the quality of the ultimate photograph eventually developed.
It is thus an object of the present invention to provide a film holder apparatus for the facilitated introduction and positive maintenance of photographic film sheets into large format field and studio cameras, which film holder precludes against undesirable shifting, sliding, bowing and or migration of the film once loaded into the holder apparatus.
It is another object of the invention to provide such a film holder apparatus, which maintains the film in accurate focusing position relative to the lens so as to preclude the need for the taking of additional "insurance" shots, while precluding the need for the photographer to develop "compensating adjustments" in his focusing or photography techniques.
Yet another object of the invention is to provide such a film holder apparatus, which precludes the inadvertent leakage of light into the film holder apparatus, by eliminating conventional fabric flap gates and abutment regions.
Other objects of the invention include the provision of a film holder apparatus of increased strength and durability, in standard large camera format sizes, which are interchangeable with a variety of brands of camera.
Additional objects include the accurate positioning of film during the film loading operation through reliance upon positive locking and indexing edges as well as reliance upon staggered internal peripheral ridges to further preclude against the leakage of light into the film holding region.
Applicant has sought to develop, by way of his invention a film holder apparatus which may be efficiently manufactured and reasonably priced, which is further capable of operating in a facilitated manner relative to the loading and unloading of film or dark slides--in an environment which separates and precludes interference between the film being loaded into the film holder, with conventional film holder spring light trap mechanisms.
These and other objects of the invention will become apparent in light of the present specification and drawings.